The subject matter disclosed herein generally relates to turbomachine rotors. More specifically, the present disclosure relates to cooling of steam turbine rotors.
As steam turbine systems rely on higher steam temperatures to increase efficiency, steam turbines, especially those utilizing drum rotor construction, must be able to withstand the higher steam temperatures so as not to compromise the useful life of the rotor. Materials that are more temperature-resistant may be used in the rotor construction, but use of such materials often substantially increases the cost of rotor components. High pressure, lower temperature steam may be used as a coolant for the rotor, but use of this coolant, from a source outside of the gas turbine, but this too can significantly increase cost of the rotor and degrades the rotor performance.
The art would well receive a lower cost solution for improving the high temperature resistance of the rotor while having a reduced negative impact on performance of the rotor.